A folding door structure having a pair of folding door sections which are coupled together by means of hinges or the like can be utilised to open or close the front opening of an enclosure such as a wardrobe, a closet or the like.
A conventional folding door structure used in such furniture is disclosed in Japanese Patent Application Disclosure No. 254,776/86 (corresponding to U.S. Pat. No. 4,726,637) and comprises guide hinges which are mounted for movement along guide rails disposed along the upper and lower front edges of the front opening of a piece of furniture and which support the door sections so that they may be folded back into a condition in which the rear side surfaces thereof overlap each other. The guide hinges are mounted in the outer edges at the top and bottom of each door section.
The guide hinge mounted at the top of a door section comprises a roller mechanism having rollers, rotatable about a horizontal axis, which can move along the guide rail, and further rollers, rotatable about a vertical axis, for determining the position of the door sections in the forward-and rearward directions with respect to the guide rail, and a hinge mechanism which supports the door section and allows it to rotate or swing.
The guide hinge mounted at the bottom portion of a door section comprises a roller mechanism having rollers, rotatable about a vertical axis, for determining the position of the door section in the forward and rearward directions with respect to the guide rail and a hinge mechanism which supports the door section and allows it to rotate or swing.
With this arrangement, when one or both of a pair of door sections which constitute a folding door covering the front portion of an article of furniture are pulled forwards in such a manner as to move them towards the opposite side or towards each other, the roller mechanisms of the upper and lower guide hinges of one or both of the two door sections are caused to move along the guide rails, and at the same time, the two door sections are folded up through the hinge mechanisms of the guide hinges in such a manner that the rear surfaces of the door sections overlap each other, whereby the front portion of the main furniture body is opened.
In the case of conventional folding door structures, constructed as described above, it is necessary to provide guide hinges having hinge mechanisms in order to support the door sections of the folding door and in the case of the upper guide hinge it is necessary to provide rollers which are rotatable about horizontal axes to support the door sections and rollers which are rotatable about vertical axes to determine the position in the forward-rearward directions of the door sections. Thus, the mechanism used to support the door sections is both complex and costly.
Furthermore, when the folding door is opened or closed, i.e. when the upper and lower guide hinges of the door sections are caused to move along the upper and lower guide rails, it is possible that, if a door section does not move correctly, the upper and lower parts of the door section may undergo different amounts of movement. In these circumstances the side edges of the door may slope and the door sections may not run smoothly during the opening and closing movements.
Moreover, since the roller mechanism of the upper and lower guide hinges of the door sections are merely placed on, or in contact with, the guide rails, there is a risk that the rollers may slip off the guide rails.
The present invention aims to alleviate the afore-mentioned problems, and it is an object of the invention to provide a folding door structure which is so constructed that the means used to support a door section of a folding door is simpler in construction and is less costly and, moreover, is effective to inhibit the door section from becoming inclined and to restore the door section to the correct orientation should it become inclined, so that the door section may be opened and closed smoothly, and the rollers do not slip off the guide rail.